This SBIR proposal intends to develop a nanocrystal biosensor, which is capable of simultaneously detecting and quantifying multiple traumatic brain injury (TBI)-specific biomarkers in relatively small volumes of whole blood (0.1-1 uL). The biosensor design utilizes the well-known size dependent photoluminescence (PL) of the semiconductor nanocrystals to label monoclonal antibodies for these brain injury-specific biomarkers such as {S-100[unreadable], D- Dimer, and CRP, etc}. The semiconductor nanocrystals as biolabels make the biosensor able to simultaneously detect multiple TBI-specific neurochemical biomarkers in one setup with a single light source due to their broad excitation spectra, and their narrow, symmetric emission spectra. A membrane filter, immobilized with multiple monoclonal antibodies, will be used as a bioseparator to specifically capture and separate these multiple TBI-specific neurochemical biomarkers from the sample while going through the microflow cell. The simultaneous detection and quantification of multiple brain injury-specific biomarkers will subsequently be accomplished by the differently sized semiconductor nanocrystal biolabeled antibodies. The simultaneous detection of multiple TBI-specific neurochemical biomarkers diminishes the false signal and improves the accuracy in assessing TBI. In comparison to existing technologies such as ELISA, this new technology will be more sensitive, reliable, specific, accurate, portable, robust, inexpensive and rapider to assess TBI. [unreadable] [unreadable] [unreadable]